Islanders captain John Tavares had a goal and assist, and Nick Leddy had two assists in what could still be the franchise's final game at Nassau Veterans Memorial Coliseum. Cal Clutterbuck then got the loud crowd on its feet to seal the win with an empty-net goal with 53 seconds remaining.
John Carlson scored for the Capitals, who will host the deciding game Monday night. The series winner advances to face the Presidents' Trophy-winning New York Rangers, who finished off the Pittsburgh Penguins in five games Friday night.
Jaroslav Halak made 38 saves -- including 13 in the final period -- and bounced back from a 5-1 loss in Game 5 on Thursday night.